LONDON – A senior political officer at the Israeli Embassy in London has been secretly filmed talking about how he would like to “take down” UK foreign office minister Alan Duncan, a vocal opponent of illegal Israeli settlement building in the West Bank.

He said Duncan, who is one of the few Conservative ministers to speak out over settlements, was causing “a lot of problems”. He also called Boris Johnson, the foreign secretary, “an idiot”.

In a separate conversation with the embassy staffer, Crispin Blunt, the chairman of the Commons Foreign Affairs Committee, was described as being “on the hit list” for his views which were “strongly pro-Arab rather than pro-Israel”.

The revelations provoked an immediate political reaction, with Desmond Swayne, a former Conservative minister and parliamentary aide to former prime minister David Cameron, calling for the incident to be “investigated thoroughly”.

“What we cannot have is Israel acting in the UK with the same impunity it enjoys in Palestine,” he told Middle East Eye. “This is clearly interference in another country’s politics of the murkiest and most discreditable kind.”

In a statement on Saturday night, the Israeli embassy said that Mark Regev, Israel’s ambassador to the UK, had spoken to Duncan to apologise and that Regev had made clear that the embassy considered the remarks to be “completely unacceptable”.